"The Messenger of Allah ﷺ bought a load of fodder from a Bedouin man. When the transaction was concluded, the Messenger of Allah ﷺ said: 'Choose (either to go ahead or to cancel the transaction).' The Bedouin said: 'May Allah grant you a long life of good transaction!"'  

اشْتَرَى رَسُولُ اللَّهِ ﷺ مِنْ رَجُلٍ مِنَ الأَعْرَابِ حِمْلَ خَبَطٍ فَلَمَّا وَجَبَ الْبَيْعُ قَالَ رَسُولُ اللَّهِ ﷺ اخْتَرْ فَقَالَ الأَعْرَابِيُّ عَمْرَكَ اللَّهَ بَيِّعًا  

I heard Abu Sa'eed Al-Khudri say: "The Messenger of Allah ﷺ said: 'Transactions may only be done by mutual consent."'  

قَالَ رَسُولُ اللَّهِ ﷺ إِنَّمَا الْبَيْعُ عَنْ تَرَاضٍ